Oxidation-Fermentation (OF) Test

Result Interpretation of OF Test

Objective of OF Test To differentiate microorganisms based on the ability to oxidize or ferment specific carbohydrates. Principle of OF Test Carbohydrates are organic molecules that contain carbon, hydrogen and oxygen in the ratio (CH2O)n. Organisms use carbohydrate differently depending upon … Read more

4-Methylumbelliferyl-β-D-Glucuronide (MUG) Test

4-Methylumbelliferyl-β-D-Glucuronide (MUG) Test

Objective of MUG Test To identify various genera of Enterobacteriaceae and verotoxin-producing Escherichia coli. Principle of MUG Test β-D-Glucuronidase is an enzyme produced by most strains of E. coli and other Enterobacteriaceae  which hydrolyzes β-d-glucopyranosid-uronic derivatives to aglycons and d-glucuronic acid. … Read more

O-Nitrophenyl-β-D-Galactopyranoside (ONPG) Test

O-Nitrophenyl-β-D-Galactopyranoside (ONPG) Test

Objectives of ONPG Test To determine the ability of an organism to produce β-galactosidase, an enzyme that hydrolyzes the substrate ONPG to form a visible (yellow) product, orthonitrophenol To distinguish late lactose fermenters from non–lactose fermenters of Enterobacteriaceae Principle of ONPG … Read more

Lysine Iron Agar Test

Result Interpretation of Lysine Iron Agar Test

Objective of Lysine Iron Agar Test To differentiate gram-negative bacilli based on decarboxylation or deamination of lysine and the formation of hydrogen sulfide (H2S). Principle of Lysine Iron Agar Test Lysine iron agar (LIA) contains lysine, peptones, a small amount of glucose, ferric … Read more

Litmus Milk Medium Test

Result Interpretation of Litmus Milk Medium Test

Objective of Litmus Milk Medium Test To differentiate microorganisms based on various metabolic reactions in litmus milk, including fermentation, reduction, clot formation, digestion, and the formation of gas.  Litmus Milk is used primarily to differentiate members within the genus Clostridium. It … Read more

Hydrogen Sulfide (H2S) Production Test

Result Interpretation of Hydrogen Sulfide (H2S) Production Test

Objective of Hydrogen Sulfide (H2S) Production Test To determine the ability of the organism to produce hydrogen sulphide. Principle of Hydrogen Sulfide (H2S) Production Test Hydrogen sulphide (H2S) production test is used for the detection of hydrogen sulphide (H2S) gas produced by an … Read more